In order to transmit data over fiber optic networks, edge-emitting lasers and Vertical Cavity Surface Emitting Lasers (VCSEL) are commonly used to generate the data carrying signal. Edge-emitting lasers, emit photons out of one edge of the wafer after the photons rebound off mirrors cleaved in the substrate. Manufacturing edge-emitting lasers requires a wafer cutting operation to expose the sides from which the laser is emitted. VCSELs, on the other hand, include mirrors grown into the surface of the structure allowing laser light to emit a cylindrical beam in a perpendicular orientation to the wafer surface. As VCSELs require no wafer cutting operation to expose the laser light, VCSELs have reduced costs for manufacturing, packaging, alignment and testing. In addition, VCSELs can be tested in an uncut state such that defects can be identified prior to the expenditure of additional processing resources.
VCSELs are frequently used in parallel optical transceiver packages to generate photons for transmission through a fiber optic cable. The VCSEL is mounted to the electronic substrate of the parallel optical transceiver package by a flexible circuit. The VCSEL can then be disposed generally transverse to the electronic substrate as the conductive path of the flexible circuit is bent approximately ninety degrees.
As adhesives are typically used to bond the flexible circuit to the electronic substrate, there is a need to insure the VCSEL works appropriately prior to mounting. If not, the VCSELs must be pried from the substrate, typically resulting in damage and higher production costs or alternatively, the entire transceiver package must be disposed of. Therefore, there is a need to test the VCSELs with the attached flexible circuit under typical operating conditions prior to mounting.